Hello, Álvaro.
I've uploaded the example scenes and images of both wrong results with the fixed bias and good (or at least better) results with auto bias calculation here. I hope this is what you wanted:
https://github.com/DavidBluecame/Blender-Exporter/releases/download/v0.1.99-beta2/Self.shadow.bias.scenes.zipI also believe this is a better fix than before. However, as povmaniaco pointed out here (
https://github.com/YafaRay/Core/pull/81) it's possibly not the best solution as there could be big scenes with small triangles.
As I wrote in my answer to him, I believe there are four choices here:
* The original system (fixed bias), but it's known to cause artifacts in some scenes and the reason why I made this change.
* Exposing the bias parameter. This is what I wanted to do, to give the users the control about it so they could solve any issues with too big or small bias. However it was decided to avoid exposing it to the user.
* This new calculation depending on scene size. Not ideal, if you have a big scene and take shots of interior details, perhaps the bias will be too big and cause artifacts. We have to see what happens now.
* A probable better option would be to do a per-triangle shadow bias/min ray dist. I already made some tests with it. However, it's more "expensive" in computation time and slows down the render. Also, there is a risk of having inconsistent shadows if the bias is different for each triangle. In any case it's the solution that I think makes more sense in the long term...
In any case, let's see what happens with this experimental version for now, please let me know if you have any issues with it.